I don't have crickets yet, but I have roaches! So for a staple they get oatmeal (which is less than ideal because phytates, but several generations later, as long as you mix things up you won't have birth defects. I fed pure oatmeal in the winter and got bad molts and deformed roaches, don't do it). I supplement with the leftovers from when my dad makes juice, so an assortment of fruit and vegetable pulp. I also give the rindes of whatever fruit I'm eating, so watermelon, apple cores, etc. Lately I've been feeding dried then frozen Hornwort from my goldfish pond, and I've never seen healthier roaches!!! They can't get enough of it, but oddly enough the algae that clings it they won't touch, and I have to pick it out. I also freeze pumpkin gook in the fall and give that once in a while. And lastly I'm experimenting with prickly pear cactus... Haven't tried it yet, but I've got several started and hoping they grow so I can feed them to bugs!